/*
  * PNM image parser

  * Copyright (c) 2002, 2003 Fabrice Bellard

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "libavutil/imgutils.h"
 

 #include "parser.h" //for ParseContext
 #include "pnm.h"
 
 

 static int pnm_parse(AVCodecParserContext *s, AVCodecContext *avctx,
                      const uint8_t **poutbuf, int *poutbuf_size,
                      const uint8_t *buf, int buf_size)

 {
     ParseContext *pc = s->priv_data;
     PNMContext pnmctx;
     int next;
 

     for (; pc->overread > 0; pc->overread--) {

         pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
     }
 retry:

     if (pc->index) {
         pnmctx.bytestream_start =
         pnmctx.bytestream       = pc->buffer;
         pnmctx.bytestream_end   = pc->buffer + pc->index;
     } else {
         pnmctx.bytestream_start =
         pnmctx.bytestream       = (uint8_t *) buf; /* casts avoid warnings */
         pnmctx.bytestream_end   = (uint8_t *) buf + buf_size;

     }

     if (ff_pnm_decode_header(avctx, &pnmctx) < 0) {
         if (pnmctx.bytestream < pnmctx.bytestream_end) {
             if (pc->index) {
                 pc->index = 0;
             } else {

                 buf++;
                 buf_size--;
             }
             goto retry;
         }

         next = END_NOT_FOUND;

     } else if (pnmctx.type < 4) {
         next = END_NOT_FOUND;

     } else {
         next = pnmctx.bytestream - pnmctx.bytestream_start

                + av_image_get_buffer_size(avctx->pix_fmt, avctx->width, avctx->height, 1);

         if (pnmctx.bytestream_start != buf)
             next -= pc->index;
         if (next > buf_size)
             next = END_NOT_FOUND;

     }
 

     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
         *poutbuf      = NULL;

         *poutbuf_size = 0;
         return buf_size;
     }

     *poutbuf      = buf;

     *poutbuf_size = buf_size;
     return next;
 }
 

 AVCodecParser ff_pnm_parser = {

     .codec_ids      = { AV_CODEC_ID_PGM, AV_CODEC_ID_PGMYUV, AV_CODEC_ID_PPM,
                         AV_CODEC_ID_PBM, AV_CODEC_ID_PAM },

     .priv_data_size = sizeof(ParseContext),
     .parser_parse   = pnm_parse,
     .parser_close   = ff_parse_close,

 };